Normal factor analysis, called "R method," involves finding correlations between variables (say, height and age) across a sample of subjects.
The sample of statements for a Q sort is drawn from and claimed by the researcher to be representative of a "concourse"—the sum of all things people say or think about the issue being investigated.
In studies of intelligence, Q factor analysis can generate consensus based assessment (CBA) scores as direct measures.
The "Q sort" data collection procedure is traditionally done using a paper template and the sample of statements or other stimuli printed on individual cards.
Q-methodology has been used as a research tool in a wide variety of disciplines including nursing, veterinary medicine, public health, transportation, education, rural sociology, hydrology, mobile communication, and even robotics.
However, Lundberg et al. point out that "[s]ince participants’ Q sorts are neither right nor wrong, but constructed through respondents’ rank-ordering of self-referent items, validity in line with quantitative tenets of research is of no concern in Q".
[10] In 2013, an article was published under the title "Overly ambitious: contributions and current status of Q methodology" written by Jarl K. Kampen & Peter Tamás.
[11] Kampen & Tamás state that "Q methodology neither delivers its promised insight into human subjectivity nor accounts adequately for threats to the validity of the claims it can legitimately make".
[12] Brown et al. states that since its inception, Q methodology "has been a recurring target of hastily assembled critiques"[12] which has served no other purpose than to misinform other researchers and readers.
[12] The authors continue on this argument by stating that "the data of Q methodology are not responses to individual statements alone, but more importantly in their relationships, as when they are rank-ordered".
[12] In their conclusion, Brown et al. point out that, much like Medici's refusal to look through Galileo's telescope, "these critics have failed to engage personally with Q in order to see if their abstract critiques hold up in practice".